Universidad de Magallanes
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Evolution of glacial lakes and southernmost GLOFs in the Cordillera Darwin and Cloue Icefields (Tierra del Fuego) between 1945-2024
No full textThe rapid retreat of mountain glaciers due to climate change has led to the expansion of glacial lakes, which can produce sudden glacial lake outburst floods (GLOFs) due to the failure of unstable moraine or glacier dams, in some cases triggering a cascade of consequences. This study investigates the evolution of glacial lakes and the occurrence of GLOFs in the Cordillera Darwin and Cloue Icefields of Tierra del Fuego, southernmost South America, from 1945 to 2024 - a region that has not been analysed in detail before. Using historical aerial imagery, satellite data, UAV photogrammetry and field surveys, we document a 461% increase in the number of lakes (from 33 to 185) and a 124% increase in lake area (from 28.2 +/- 5.6 to 63.3 +/- 1.9 km2) as a result of glacier retreat. A pronounced shift from ice-dammed (71.6%-14.8% of the total area) to moraine-dammed lakes (80.5% by 2024) reflects the destabilisation of the ice margins and the exposure of overdeepened basins. We identified the first recorded southernmost GLOFs in this region, including a moraine collapse in 1997/98 that released similar to 8.3 +/- 1.2 x 106 m3 of water and a larger, adjacent cascading event in 2018 that released 28.3 x 106 m3 of water through successive moraine dam breaches. The cyclic outflows of the ice-dammed Lago Mateo Martinic (1985-2024) underline the dynamic interactions between ice and water. The results are consistent with global patterns of accelerated lake formation and growth over the last century, and with the diverse and complex processes at GLOFs that make Tierra del Fuego an important natural laboratory for studying the deglacierising environment. This study improves the understanding of glacial lake dynamics in the little-studied southern latitudes and emphasises the accelerated transformation of Andean cryospheric landscapes as warming progresses
Real-World Data on Inotuzumab Ozogamicin for Adult Patients With Relapsed/Refractory Acute Lymphoblastic Leukemia: A GRELAL-Chile Study
No full textBackground Inotuzumab Ozogamicin (InO) has shown efficacy in relapsed/refractory acute lymphoblastic leukemia (R/R ALL), but evidence from Latin America is scarce. We evaluated the outcomes of Chilean patients treated with InO in public and private health centers. Methods We retrospectively analyzed 35 patients with R/R ALL (median age 33 years; 54% male). Twenty percent had BCR::ABL-positive ALL, 78% expressed CD22, and 91% expressed CD19. Response rates, measurable residual disease (MRD), survival outcomes, and treatment-related toxicities were assessed. Multivariate analyses explored prognostic factors. Results Complete remission or remission with incomplete recovery (CR/CRi) was achieved in 74% of patients. Among those evaluated, 82% reached MRD < 0.01%. Patients undergoing allogeneic hematopoietic stem cell transplantation (Allo-HSCT) after InO had superior overall survival (OS) compared with those who did not (24.2 vs. 5.2 months). Median progression-free survival (PFS) was 6.9 months and median OS was 8.8 months. Sinusoidal obstruction syndrome occurred in 14% of patients but was generally mild. Multivariate analysis identified comorbidities and high blast counts as adverse prognostic factors, whereas MRD negativity and subsequent Allo-HSCT were associated with improved outcomes. Conclusions InO demonstrated high remission and MRD negativity rates in Chilean patients with R/R ALL, with OS and PFS comparable to existing research. Although SOS incidence was higher, it was generally mild. Achieving MRD negativity and proceeding to Allo-HSCT provided the greatest survival benefit. Study limitations include short follow-up and limited data
Permafrost and active layer characteristics in the high arid Andes between the Altiplano and high Atacama Desert
No full textThe thermal and hydrological regime of permafrost in the arid Andes is unique due to the combination of extreme aridity, high solar radiation, and significant diurnal temperature fluctuations. Drilling at Chachani (6,057 m.a.s.l.), Aucanquilcha (6,176 m.a.s.l.), Chajnantor (5,640 m.a.s.l.), and Ojos del Salado (6,893 m.a.s.l.) volcanoes revealed both dry permafrost and ice-rich permafrost in one of the driest areas on Earth. We monitored solar radiations and ground temperature conditions at twenty-four sites on eleven mountains between 1 degrees and 33 degrees S. At elevations above 5,800 m, the active layer is about 10 to 30 cm thick and is controlled by diurnal fluctuations. Near the lower limit of mountain permafrost (LLMP), the thermal offset is positive and ice-rich terrains are found that are associated with moisture percolating from penitentes. Above 6,400 m, the surface energy balance is dominated by sublimation and dry permafrost was found. Near LLMP elevation, snow ablation was dominated by melting during summer, and ice-rich permafrost was present. We found that the type of snow ablation varies with elevation and affects the thermal properties of the permafrost in the arid Andes
Gender perspective and sexual diversities in the curriculum of Occupational Therapy at the Universidad de Magallanes
No full textResumen Introducción Esta investigación se centra en conceptos de diversidad sexual, perspectiva de género y currículo; evidenciando si estos se encuentran o no presentes, en la formación de pregrado de Terapia Ocupacional de la Universidad de Magallanes de Chile. Objetivo Conocer la existencia y manifestaciones de las perspectivas de género y diversidades sexuales en el currículo de terapia ocupacional. Método Estudio mixto, con alcance descriptivo y diseño feminista con perspectiva de género, donde se recolectan datos de documentos oficiales (plan de estudios y programas de asignaturas) y desde las experiencias, vivencias y relatos de estudiantes y docentes. Resultados Respecto al plan de estudios de la carrera de Terapia Ocupacional 2020, se puede observar uso preferente de masculino, inexistencia de estrategias tipográficas, desdoblamiento, u otras estrategias alternativas. En relación al uso del lenguaje incluyente en los programas de la carrera, se revisaron un total de 23 programas de asignatura, en los cuales se aprecia que existe un esfuerzo mayoritario por ser incluyentes, siendo las estrategias más utilizadas el uso de expresiones neutrales y formas impersonales. En cuanto a las percepciones de docentes y estudiantes sobre la inclusión de perspectivas de género y diversidades sexuales en el currículo oculto de la carrera de Terapia ocupacional y las estrategias de aula, se evidenció que ambos grupos reconocieron la importancia de estos enfoques para un aprendizaje más equitativo. Conclusion Se observa una evolución a lo largo del tiempo, con prácticas más inclusivas, siendo necesario aún más desarrollo
Association between motor competence, sex, age, and risk of obesity in children from the austral zone of Chile
No full textMotor competence (MC) is crucial for promoting an active lifestyle. Endogenous factors such as age, sex, and weight status influence its development. The prevalence of physical inactivity and obesity is concerning, especially in the most southern area of Chile, which is characterised by its isolated geography and extreme climate. This study aimed to determine the level of motor competence in children from the southernmost region of Chile at the onset of primary education and to analyze the association between MC, sex, age, and risk of obesity. The study included 830 schoolchildren (55.7% girls, age M = 7.51) from 1st and 2nd grades. Motor competence was assessed using the MOBAK 1-2 test, and the risk of obesity was measured using the waist-to-height ratio (WHtR). Results showed that motor competence levels were generally between "needs improvement" and "acceptable performance." Structural equation modelling revealed significant associations between motor competence and age (object control only), sex (boys with object control and girls with self-movement), and WHtR (self-movement only). This study highlights the importance of considering these factors to improve the motor competence of children from this region
Vegas (Mallínes): Patagonian wetlands still underexplored by soil science. An international and multidisciplinary effort to highlight their soil-based ecosystems functions
No full textPatagonian "Vegas" are unique wetland ecosystems located in the arid and semi-arid steppe of Austral Patagonia (41–55°S), a region that remains largely unexplored by soil science, despite its ecological importance. Therefore, this study aims to assess the contribution of Vegas to key soil-based ecosystem functions—biomass production, water regulation, carbon sequestration, and nutrient content—and to evaluate their degradation status through a classification soil-based model. To meet the objectives of this study, a global bibliometric analysis (4283 publications) and a regional bibliometric analysis (55 publications) were carried out. Meanwhile, it produced a descriptive statistical summary (with 998 data points) and classification models for the ecological condition of the Vegas (with 322 data points). Compared with the vast number of wetland studies conducted in the Northern Hemisphere, our regional bibliographic analysis revealed a relative scarcity of research focused on Patagonian Vegas. Furthermore, our results demonstrate that well-preserved Vegas store up to 300 Mg C ha−1, hold an average of 8500 m3 water ha−1 (0–200 cm depth), and maintain high productivity across diverse hydrological and landscape gradients. Degradation, however, can reduce these capacities by up to 20 %. Using key soil parameters such as—pH, organic carbon, water holding capacity, and electrical conductivity—a Random Forest model was developed to classify the soil ecological condition of Vegas, achieving an overall classification accuracy of 67 %. This work highlights the role of Patagonian Vegas as critical carbon and water reservoirs, which is particularly relevant due to the ongoing climate warming where exacerbated organic C decomposition can take place. Furthermore, we state a clear definition of Vegas to use by future conservation and land-use strategies. Given their high vulnerability to grazing, agricultural and other management pressures, the implementation of climate-based monitoring tools is critical to safeguard their ecological integrity and to ensure the sustainable provision of ecosystem services in one of the world's most climate-sensitive regions
Social-ecological vulnerability of small-scale farming in the southern Andes: the role of Indigenous and Local Ecological Knowledge in adaptation to climate variability
No full textSmall-scale farming is highly vulnerable to climate variability due to the increased uncertainty in production processes caused by short-term changes in precipitation and temperatures. We investigated the key factors behind the social-ecological vulnerability to climate variability of small-scale farming in the southern Chilean Andes. We adopted a mixed methods approach that included climate variability data at the basin level, semi-structured interviews, characterization data sheets and participant observation. The data was analyzed according to three dimensions of vulnerability: exposure, sensitivity and adaptive capacity. Our results reveal the significant interannual variation in accumulated seasonal precipitation and the frequency and intensity of drought events in the basin. Also, we found that small-scale farmers perceive social-ecological vulnerability through the impact on their daily practices and experiences. They view water as a common resource that depends not only on climatic conditions, but also on treatment of the ecosystem that maintains it. We observe that collective adaptation strategies, such as fairs, traditional festivals, and cooperatives organized by small-scale farmers, enhance adaptive capacity by increasing income, which enables investment in equipment, technology, and inputs for adapting production systems to climate variability. We conclude that individual adaptive capacity does not suffice to address the exposures and sensitivities that produce social-ecological vulnerability. It is, therefore, key to design collective adaptation strategies of a local and participatory nature that incorporate Indigenous and Local Ecological Knowledge
REGULATION OF BUSINESS CONGLOMERATES IN CHILE: A NORMATIVE AND DOCTRINAL DESCRIPTION
No full textThe current economic situation in Chile shows that business conglomerates, also called holding companies, represent a strong basis in the country's economic development. These groups of companies imply links in ownership and management, although each associated company has its own legal personality. Thus, these different legally independent companies act administratively under the strategic direction of a central entity, called the parent company. The objectives of the research refer to: [1] conceptualize business conglomerates in Chile; [2] to identify and describe the different types of links that define the precept of business conglomerate in Chile; [3] Describe and analyze the economic, financial, labor and tax regulations applicable to business conglomerates in Chile. This study is defined as qualitative, descriptive, and situational research. The methodology applied is structured through a non-experimental design, from a qualitative perspective and the techniques of documentary and content analysis are applied. The results obtained show that the legal figure of corporations is the basis of the structuring and relationship of these groups of economic concentration, that Chilean legal norms strongly condition the actions of business conglomerates, but that they can act freely in their corporate aspects, to the extent that their acts are within the current legal framework. The main conclusions indicate that a business conglomerate exists when a group of companies have a corporate structure of parent company and subordinate companies, with common purposes and business management unity. In tax matters, the regulation recognizes Tax Planning as valid, but the auditing entity can qualify the actions of companies as abusive or simulation acts. In the financial sphere, the prohibited acts are operations between companies and related persons and what is required is transparency in the delivery of corporate information. In the economic sphere, FNA not only acts according to the unlawful acts explicit in the rules but also has the power to qualify as contrary to free competition, any strategy of a conglomerate that could potentially produce negative consequences in the markets
Patterns of Directional and Fluctuating Asymmetry in Southern Ocean Sea Urchins
No full textBilateral symmetry is a fundamental organizational trait in many metazoans. However, deviations from this symmetry, manifested as directional or fluctuating asymmetries, offer valuable insights into developmental, functional, and environmental processes. This study quantified and characterized bilateral asymmetry in three related species of the genus Abatus using a dual approach that integrates linear and geometric morphometrics. Our analyses reveal consistent patterns of directional asymmetry across different species, with specific trends showing that the left body sides tend to be larger. In contrast, fluctuating asymmetry exhibited an inverse relation with directional asymmetry. Also, linear morphometric analysis showed no significant correlation between directional asymmetry and either sex or body size, while geometric analyses only identified subtle shape deviations related to size but not to sex. These findings allow us to discuss the possible origins of this trait, mainly related to developmental constraints due to reproduction or growth, or carried over on a genetic basis. Our results highlight the importance of combining different morphometric approaches to clarify complex patterns of morphological variation and emphasize the significance of asymmetry analyses in understanding evolutionary and ecological processes in irregular echinoids
Fault Diagnosis in a 2 MW Wind Turbine Drive Train by Vibration Analysis: A Case Study
No full textThis paper presents a vibration analysis method for detecting typical faults in gears of the drive train of a 2 MW wind turbine. The data were collected over a one-year period from an operating wind turbine with a gearbox composed of one planetary stage and two helical gear stages. Failures in two pairs of helical gears were identified: one involving pitting and wear in the gears connecting the intermediate-speed shaft to the low-speed shaft, and another one involving significant material detachment in the gears connecting the intermediate-speed shaft to the high-speed shaft. The continuous evaluation of time signals, frequency spectra, and amplitude modulations allowed the most sensitive sensors and frequencies for predicting surface damage on gear teeth in this type of turbine to be determined. A steady-state frequency analysis was performed, enabling the detection of the aforementioned surface faults. This approach is simpler compared with more complex transient-state techniques. By tracking vibration signals over time, the importance of analyzing gear mesh frequencies and their harmonics was highlighted. Additionally, it was found that the progression of gear damage was dependent on the power output of the wind turbine. As a result, the most appropriate ranges of power were identified, within which the evolution of the vibration measurement was associated with the damage evolution. Since many turbines currently in operation have similar designs and power output levels, the present findings can serve as a guideline for monitoring an extensive number of units